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Klein Tools RT250 GFCI Outlet Tester with LCD Display, Electric Voltage Tester for Standard 3-Wire 120V Electrical Receptacles

  • Based on 10,899 reviews
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Style: Receptacle Tester


Features

  • CLEAR LCD READOUT: GFCI Receptacle Tester features a large backlit LCD readout for easy voltage reading and clear indication of wiring conditions
  • TRIP TIME DISPLAY: LCD readout shows the time required to trip a GFCI device, allowing for quick and accurate troubleshooting
  • DETECT COMMON WIRING FAULTS: Detect and identify common wiring faults, ensuring electrical safety and proper functionality of GFCI receptacles
  • PATENT-PENDING OPEN NEUTRAL & OPEN GROUND DETECTION: Innovative detection system identifies Open Neutral and Open Ground wiring faults, enhancing safety measures
  • CONVENIENT AUTO-HOLD FEATURE: Auto-Hold function holds the reading for hard-to-reach outlets, providing convenience and ease of use
  • VISIBLE LED INDICATORS: Bright green and red LEDs illuminate to provide clear visual indicators of wiring conditions, making it easy to identify issues
  • CAT II 135V SAFETY RATING: GFCI Receptacle Tester has a CAT II 135V safety rating, ensuring reliable and safe electrical testing for various applications

Description

The RT250 is an electrical receptacle tester that tests the wiring conditions at an electrical outlet and inspects GFCI devices. The LCD displays the voltage, identifies the wiring fault, and the time required to trip a GFCI device. It is designated for use with North American 3-wire 120V electrical outlets. For more than 160 years, Klein Tools has manufactured premium- quality, professional-grade hand tools that deliver the performance, durability and precision needed to get the job done right. Our family of engineers, workers and craftsman continue to put six generations of expertise into every tool we create by using only the highest quality materials, superior workmanship, and keeping manufacturing as close to home as we can. Klein isn't just the name of our company, it's also our family name. And since we're an American company that's family-owned and family-run, you know you can count on us to be here tomorrow. Klein Tools doesn't just make great products, we make great products that stand up to the demands of the professionals who use them every day ... Since 1857.

Specs & Other Info

Specification Details
Brand Klein Tools
Energy Type Operates on Batteries
Design Receptacle Tester
Color Scheme Combination of Green and Red
Weight Lightweight at 4.16 Ounces
Manufacturer Continuation Continuous production, not Discontinued
Dimensions Compact size, 4.53 x 1.16 x 2 inches and 4.16 Ounces
Model Number Designated as RT250
Target Audience Applicable for both Men and Women
Batteries Requires 2 AAAA batteries (provided)
Available Since First introduced on December 17, 2020
Manufacturer Produced by Klein Tools
Made In Originates from China
Selling Rank #1,598 in Tools & Home Improvement, #3 in Circuit Testers

Frequently asked questions

The Klein Tools RT250 is an electrical testing tool, specifically designed to test standard 3-wire 120V electrical receptacles. It can measure the voltage and indicate whether the GFCI (Ground Fault Circuit Interrupter) is properly functioning. This would be helpful in preventing electric shocks.

The LCD display on the RT250 is an essential feature that provides a clear digital presentation of the voltage present in the outlet. The LCD display is also used to explain the wiring condition symbols that might appear on the device. It is designed to make testing more accurate and easy.

The Klein Tools RT250 Outlet Tester comes in two colors, red and green, to provide an easy and clear indication of the status of the electrical receptacle. Green indicates that the outlet is properly wired, while red signals that there is a problem with the wiring.

The Klein Tools RT250 Outlet Tester provides an essential service in preventing electrical shocks. By testing whether the GFCI of an outlet is properly functioning, the device ensures that dangerous electrical faults are detected immediately. This allows for early intervention and prevention of potential harm.

Top Amazon Reviews

🚀 Abunda's Overview

This is our summary and key points to consider based on customer reviews.


The product under review appears to be an exceptionally reliable and effective tool for electrical testing. It piques a high degree of satisfaction among users who have employed it for various tasks such as installing GFI plugs, testing power supplies, and verifying proper outlet wiring. Its distinct feature seems to be its voltage readout, which users particularly admire and find superior to other similar products. Despite its excellent rating, one user pointed out a minor inconvinience with the display positioning.

Pros

  • 👍 Highly effective for a range of electrical tasks.
  • 👍 Voltage readout feature is superior to other market options.
  • 👍 Potentially saves significant money by preventing electrical mishaps.
  • 👍 Easy to use and convenient to carry around.

Cons

  • 👎 The display may be inconveniently positioned for some installations.

Should I Buy It?

If you're in need of a reliable, user-friendly, and effective tool for various electrical tasks, this product comes highly recommended by multiple users. Its ability to provide voltage readout sets it apart, and it's been praised for its potential to save significant money by preventing electrical mishaps. Despite one minor issue with the display positioning, the overwhelmingly positive feedback suggests this product could be a valuable addition to your toolkit.


  • Simple and easy to use yet Amazing precision!!!
Style: Receptacle Tester
I picked up the Klein Tools RT250 GFCI Outlet Tester to help check a few outlets around my house, and I’m honestly impressed. This thing is super straightforward, just plug it in, the lights pop on, and you instantly know what’s going on with the wiring. No guesswork, no complicated setup, just clear results. The display is bright and easy to read, and the built-in GFCI test button is a lifesaver when checking bathroom and kitchen outlets. It helped me identify a miswired outlet in an older part of my house that I never would’ve caught otherwise. For something at this price, it feels durable and professional like something an electrician would actually use. If you’re a homeowner, DIYer, or just want peace of mind about the electrical safety in your place, this is a solid buy. Fast, accurate, and super easy to use. Highly recommend! ... show more
Reviewed in the United States on December 31, 2025 by Dan Draughon Dan Draughon

  • Best GFCI Outlet Tester Available
Style: Receptacle Tester
This review is for Klein Tools RT250 GFCI Outlet Tester with LCD Display, Electric Voltage Tester for Standard 3-Wire 120V Electrical Receptacles. This is the best outlet tester I have seen so far. I love the backlit readout and that it gives you the voltage information too. All the features, including the GFCI test, work flawlessly. I have never had a Klein tool that I have been unhappy with, and I find this tester to be a great value. ... show more
Reviewed in the United States on January 1, 2026 by MADPWR

  • Essential Tool for Electricians and DIY Pros
Style: Receptacle Tester
As an electrician or serious DIY-er who cares about doing things right, this tester has quickly become one of my favorite go-to tools. The RT250 is packed with features and built to handle real-world job-site demands. What stands out: The large back-lit LCD display clearly shows voltage, wiring condition, and the time it takes a GFCI to trip—making testing thorough and faster. It automatically detects open neutral, open ground, and other common wiring faults—no more guesswork. The built-in GFCI test button trips the device and the timer measures how long it takes—great for verifying that the GFCI meets spec. Rugged build: rated for a 6.6-foot (2 m) drop and meets CAT II 135 V safety rating—solid for a busy job site. It’s compact and lightweight (just 4.8 oz) but feels tough—durable housing and robust plug make it practical for everyday use. My experience on the job: I’ve used this tester across new installs, upgrades, and troubleshooting older receptacles. It quickly flags incorrect wiring (open ground, reverse hot/neutral, etc.), and the extra info like voltage readout and trip time saves me from coming back later for retests. Switching between circuits is fast, the screen holds readings with Auto-Hold (perfect for hard-to-reach outlets), and the indicator LEDs still give quick visual cues when I want them. Final verdict: If you’re working with North American 3-wire 120 V outlets (especially ones with GFCI protection), this tester hits all the right notes: precision diagnostics, rugged build, and efficient troubleshooting. It’s built like a pro tool—and priced so that it’s worth having in your bag every day. I highly recommend it. ... show more
Reviewed in the United States on October 22, 2025 by John

  • Great Tool for Electrician and Electrical Jobs
Style: Receptacle Tester
Great tool or electrician or noncertified electrician who cares about doing their jobs the right way. The large back-lit LCD shows voltage, wiring condition, and more info including detects open neutral, open ground, and other common wiring errors
Reviewed in the United States on December 26, 2025 by Nader

  • Good
Style: Receptacle Tester
Works well
Reviewed in the United States on November 7, 2025 by Tman

  • another fine tool by Klein tools.
Style: Receptacle Tester
in the field i work i need a reliable circuit tester, this is one i recommend, i got another one for a co worker, since he liked the way mine worked, he is really enjoying it, if you work on electrical, get one it is well worth the price and the headaches it saves.
Reviewed in the United States on December 24, 2025 by metalmadman68

  • Reliable, safe, and easy-to-use electrical tester
Style: Receptacle Tester
This outlet tester gives me a lot of peace of mind when working around the house. It’s simple to use—just plug it in, and the bright LCD display gives clear, easy-to-read results. The color-coded indicators and built-in GFCI test function make it incredibly functional for quickly checking outlets and ensuring wiring is safe. It’s also reassuring to know I’m catching potential issues before they become bigger problems. The build quality feels solid and durable, so I don’t worry about it failing when I need it most. It works well every time I’ve tested it, even compared to a more expensive professional tester. This is a perfect tool for homeowners or DIYers looking for something safe, accurate, and functional to check their electrical systems. ... show more
Reviewed in the United States on July 22, 2025 by ChrisFromTexas ChrisFromTexas

  • Klein Tools RT250 GFCI Outlet Tester with LCD Display, Electric Voltage Tester
Style: Receptacle Tester
Klein tools are known for making great product and this one has great built quality. Very easy to use and great features for my needs. Love the memory and the LCD backlight feature. Definitely recommend getting one of these testers for your DIY around the house or jobsite.
Reviewed in the United States on November 24, 2025 by Extreme DIY Extreme DIY

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